1. Field of the Invention
The invention relates to a bladed rotor of a turbo-machine, in which the blade roots and the blade grooves are made pinetree-shaped with a plurality of indentations and teeth, with the result that a plurality of supporting surfaces extending obliquely are formed, the indentations, adjoining the supporting surfaces, in the blade root and in the blade groove being described essentially by a first curve radius and a second curve radius.
2. Discussion of Background
Bladed rotors of this type are known from GB-A-2,011,522. Each blade has, in its root region, indentations and teeth which hook into the correspondingly shaped teeth and indentations in the longitudinal grooves of the rotor. The indentations are described by two radii, a larger outer radius and a smaller inner radius. On the rotor, the larger radius is located further outwards radially relative to the rotor axis. On the blade, the larger radius is located further inwards radially relative to the rotor axis. When the rotor is in operation, centrifugal forces act on the blades and are compensated for by the rotor via the supporting surfaces formed by the indentations and teeth.
As a result of the above-described design of the teeth and indentations, a narrow gap between blade and rotor is formed adjacently to the supporting surfaces. This gap has the effect of a capillary, and, adjacently to the supporting surfaces, this can cause corrosion and pitting. This can lead to premature fatigue fractures in the blade root or in the groove of the rotor. Moreover, abrasion particles which have occurred during the operation of the rotor may penetrate into the gaps, remain there and possibly destroy protective layers applied to the surfaces.